Flexitallic Gaskets Design_Criteria

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Flexitallic spiral wound gasket design criteria

Transcript of Flexitallic Gaskets Design_Criteria

Gasket Design Criteria Table of ContentsPage Worldwide Customer Service Network Introduction Section I - Gasket Selection Soft Cut Gaskets .............................................................................................................................. Thermiculite ................................................................................................................................... PTFE Products - Sigma ................................................................................................................ PTFE Products - Fluoroseal ............................................................................................................ Flexitallic Flexicarb .......................................................................................................................... Compressed Fiber Gaskets ............................................................................................................. Sheet Materials Chemical Compatibility Chart ................................................................................. Insulating Sets .................................................................................................................................. Metal Jacketed Gaskets ................................................................................................................... Spiral Wound Gaskets ................................................................................................................... Sizing Parameters for Spiral Wound Gaskets ................................................................................. Flexpro Gaskets .............................................................................................................................. MRG Gaskets ................................................................................................................................. Ring Type Joints .............................................................................................................................. Specialized Ring Type Joints .......................................................................................................... Lens Rings ....................................................................................................................................... Weld Gaskets .................................................................................................................................. Section II - Joint Integrity Calculations ASME Boiler & Pressure Vessel Code Calculations ........................................................................ PVRC Method .................................................................................................................................. Section III - Gasket Installation Bolt Torque Sequence ..................................................................................................................... Troubleshooting .............................................................................................................................. Metallic Gasket Materials ................................................................................................................ Useful Material Data ........................................................................................................................ Bolting Data ..................................................................................................................................... Useful Technical Data ...................................................................................................................... Torque Required To Produce Bolt Stress ........................................................................................ Ordering Flexitallic Gaskets for Special Flange Designs ................................................................. Metric Unit Conversions .................................................................................................................. Terms ................................................................................................................................................ 2 3 4 6 7 10 12 13 14 15 18 19 22 29 31 32 33 35 36 37 38 39 43 45 47 49 51 53 54 56 58 59 61 62

Welcome to the Next Generation of Sealing Technology

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Worldwide Customer Service NetworkOwned Manufacturing PlantsFlexitallic Ltd. Cleckheaton,Yorkshire, UK Tel: +44 1274 851273 Flexitallic Ltd. Rochdale, Lancashire, UK Tel: +44 1274 851273 Flexitallic L.P. Deer Park,TX, USA Tel: +1 281 604 2400

Licensees - contd.Dragon Industrial Services Pembroke, UK Tel: +44 1646 622200 Engineering & Chemical Productions Lagos State, Nigeria Tel: +234 1 804 3808 Eriks BV. Rotterdam, Netherlands Tel: +31 72 514 1514 Eriks Pte Ltd. Singapore Tel: +65 62 72 24 05

Joint VenturesEquiter S.A. de C.V. Guadalajara, Mexico Tel: +52 3 612 8483

GB&G Die & Gasket Co., Inc. New Orleans, LA Tel: 800-522-9613 GHX, Inc. Houston, TX, USA Tel: +1 713 222 2231 Greenville Rubber & Gasket Greenville, SC, USA Tel: +1 864 235 2574 Henry Gallacher Ltd. Stockton, Teesside UK Tel: +44 1642 750111 Industrial Gasket & Supply Torrance, CA, USA Tel: +1 310 530 1771 James E. Dooley Co. Broomall, PA, USA Tel: +1 610 328 2720 Lake Charles Rubber Lake Charles, LA, USA Tel: +1 337 433 1002 Liaoning Cartec Sealing Technologies, Inc. Benxi City, China Tel: 86 414 481 3300 Saudi Gasket Factory Jeddah, Saudi Arabia Tel: +996 2 665 2966 Special Piping Material Ltd. Delta State, Nigeria Tel: +234 53 254 767 Specialised Gaskets PTY Ltd. Auckland, New Zealand Tel: +64 98284119

Branch Offices & WarehousesFlexitallic Ltd. Aberdeen, Scotland, UK Tel: +44 1224 725241 Shanghai Zone Sealing Products Shanghai China Tel: +86 21 5812 8117

LicenseesSpecialised Gaskets Pty. Ltd. Brisbane, Australia Tel: +61 73 268 0666 AGS Group Inc. Edmonton, Alberta, Canada Tel: +1 780 466 5050 Capital Rubber & Specialty Baton Rouge, LA, USA Tel: +1 225 356 2451 Cartec Sealing Technologies, Inc. Seoul, Korea Tel: +82 2 549 5441

Note: Over 500 stocking distributors in over 40 countries strategically located to serve the world.

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Welcome to the Next Generation of Sealing Technology

FLEXITALLIC GASKET DESIGN CRITERIA IntroductionFLEXITALLIC, the worlds leading manufacturer and supplier of static seals and the originator of the Spiral Wound Gasket, is committed to sealing solutions for todays industry. With greater emphasis than ever before placed on joint tightness, more attention is focused toward variables associated with the integrity of the bolted gasketed joint. Flexitallic Gasket Design Criteria manual offers the engineer and end user assistance in meeting the goal of providing fundamentally sound static sealing practice. Developed and collated by Flexitallics worldwide team of engineers, this publication is the engineers handbook of static seals technology. Flexitallic has identified three factors which must be considered to achieve a leaktight joint Gasket Selection Gasket Design Gasket Installation

The GasketA gasket is a compressible material, or a combination of materials, which when clamped between two stationary members prevents the passage of the media across those members. The gasket material selected must be capable of sealing mating surfaces, resistant to the medium being sealed, and able to withstand the application temperatures and pressures.Overcoming Flange ImperfectionsDistortion trough Scorings

How Does It Work?A seal is effected by the action of force upon the gasket surface. This force which compresses the gasket, causes it to flow into the flange macro and micro imperfections. The combination of contact stress, generated by the applied force between the gasket and the flange, and the densification of the gasket material, prevents the escape of the confined fluid from the assembly.Surface imperfections Non-parallel mounted flanges

Flange ImperfectionsOn seating, the gasket must be capable of overcoming the macro and micro imperfections. Macro defects are imperfections such as flange distortions, non-parallelism, scoring, troughs, while superficial imperfections such as minor scratches and minor scores are considered micro imperfections.Bolt Load

Forces On The GasketIn order to ensure the maintenance of the seal throughout the life expectancy of the assembly, sufficient stress must remain on the gasket surface to prevent leakage. The residual bolt load on the gasket should at all times be greater than the hydrostatic end force acting against it. The hydrostatic end force is the force produced by the internal pressure which acts to separate the flanges.

Hydrostatic End Force

Blow Out Force Gasket

Considerations For Gasket SelectionsMany factors should be considered when selecting a gasket to ensure its suitability for the intended application. Gasket properties as well as flange configuration and application details are part of the selection process.Internal Pressure is exerted against both the flange and the gasket.

Welcome to the Next Generation of Sealing Technology

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SECTION I Gasket SelectionGaskets can be classified into three categories: soft cut, semi-metallic and metallic types. The physical properties and performance of a gasket will vary extensively, depending on the type of gasket selected and the materials from which it is manufactured. Physical properties are important factors when considering gasket design and the primary selection of a gasket type is based on the following: Temperature of the media to be contained Pressure of the media to be contained Corrosive nature of the application Criticality of the application

Soft CutSheet materials are used in low to medium pressure services. With carefu